California Code, Health and Safety Code - HSC § 39619.5

(a) The monitoring method selected shall be capable of accurately representing the spectrum of compounds that comprise PM 2.5 in the atmosphere of regions where monitoring is conducted, including nitrates and other inorganic compounds, as well as carbonaceous materials.

(b) To the extent feasible, the state board shall consider approved federal particulate methods in selecting a monitoring method for the program.

(c) The monitoring network used in the program shall site monitors so as to characterize population exposure, background conditions, and transport influence, and attain any other objective identified by the state board as necessary to understand conditions and to provide information for the development of control strategies.

(d) Portable monitors shall be used in locations not now monitored for PM 10, but where elevated PM 2.5 might be expected.

(e) During the initial two years of expanded monitoring, PM 2.5 monitoring shall be done at one or more of the highest level PM 10 sites in any region that violates the federal ambient air quality standard for PM 10, to enable a determination of the correlation between levels of PM 10 and PM 2.5.

(f) In regions where ambient source characterization studies for PM 2.5 have not been completed, the state board shall work with the district to develop and conduct those studies.

(g) The state board shall place on its Web site, updated at a minimum January 1 of each year, the status and results of the airborne fine particulate air pollution monitoring program.